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Why Teach About Bay Grasses?

by
Sarah Brzezinski

Bay grasses, also known as submerged aquatic vegetation or SAV, are plants that grow underwater. They are found in the shallow waters of the Chesapeake Bay and its streams, creeks and rivers. Bay grasses are a critical part of the Chesapeake Bay ecosystem. They serve many significant ecological functions in the Bay and its tributaries, such as adding oxygen to the water, reducing shoreline erosion, providing underwater life with food and habitat, and improving water quality by trapping sediment. Bay grasses also absorb nutrients, such as nitrogen and phosphorous, and convert them into organic matter that other aquatic life can use.

Why Should YOU Teach About Bay Grasses?

Scientific information dating back to 1937 suggests that close to 200,000 acres of bay grasses may have once grown along the Bay’s shorelines. However, by 1984, bay grass acreage had fallen to a low of about 38,000 acres. Even today, nutrient and sediment pollution in the water has choked or eliminated bay grasses in many areas, contributing to acreage declines throughout the Bay.

Although bay grasses are sensitive to pollution, they respond fairly quickly to improvements in the Bay’s condition. Scientists believe that having more grasses in the Bay and rivers will dramatically improve the entire ecosystem. The expectation is that as nutrient and sediment pollution decrease and water clarity improves, underwater grass acreages should expand. Experts closely monitor underwater grasses because their well-being is dependent on good local water quality. Therefore, their abundance and density are excellent measures of the Bay’s health.

How Can YOU Teach About Bay Grasses?

There are many great ways to teach about bay grasses in your classroom. Below, we have selected some resources to help you get started.

Featured Lesson Plans and Activities:

  • “What’s Killing the SAV?” Thinkport BayLab - In this 3-part interactive lesson, students will explore an ongoing situation in the Chesapeake Bay: the disappearance of large meadows of underwater grasses, collectively known as SAV, or submerged aquatic vegetation. They will read background and general information about the SAV, review current data about the population of the grasses, and learn why SAV are important to the Bay.
  • Grasses, Grasses Everywhere Lesson Plan - Students will investigate the properties of submerged aquatic grasses and compares them to the grass in the schoolyard. Students will learn how to observe, analyze, classify and compare grasses, organize their findings into meaningful categories, and compare and contrast two different types of grasses.
  • Photosynthesis and Respiration in Seagrass Lesson Plan - Students conduct a hands-on science experiment focusing on how different levels of light affect photosynthesis in seagrass. This lesson is aligned to National Science Education Standards and was developed by Dr. Laura Murray, University of MD Center for Environmental Science, Horn Point Laboratory.
  • “Who Killed SAV?” Lesson Plan - This lesson plan from the Virginia Department of Education instructs students to examine four major causes of bay grass decline. Students will also defend, compare, and discriminate between arguments for and against a given factor and will evaluate the level to which certain natural and human factors led to the decline of bay grasses.
  • Build-A-Bed Activity - In this activity from the Virginia Coastal Zone Management Program and the Virginia Institute of Marine Science, students will build an aquatic grass bed in a small wading pool and populate it with some of the species that inhabit the aquatic grass bed. Engaging children in this activity helps teach them how submerged aquatic vegetation provides essential habitat for blue crabs, young stripped bass, and other animals.
  • Bay Backpack Teacher Resources - Additional teacher resources about bay grasses.

Other Resources:

  • Chesapeake Bay Grasses Interactive Map – This is an excellent resource to bring decades of real world, Chesapeake Bay data to life your classroom! Using information related to water quality and the abundance of underwater grasses, this interactive map tracks changes in Bay health over time. Move through a 30-year timeline to watch fluctuations in water temperature, salinity and turbidity take place alongside changes in grass abundance, as dominant species ebb and flow and grass beds shrink and expand. Incorporate this resource into lessons about water chemistry, estuaries, habitats, and more!
  • Learn the Issues: Bay Grasses – Have your students learn more about underwater grasses in the Bay: their role as a food source and habitat, the factors that can affect their growth and the ways in which vital beds are being restored.
  • Bay Field Guide: Bay Grasses (SAV) - Close to 20 species of submerged aquatic vegetation can be found in the Bay and its tributaries. Use this online Field Guide to learn more about these grasses. This is a great informational resource to send students to for reports or group projects.
  • Photo Essay: Biologists track bay grass abundance for clues about water quality - The abundance of underwater grasses can tell us a lot about the health of the Chesapeake Bay. This photo essay follows scientists and volunteers as they sample grasses to gauge water quality. Not only will it help your students understand the importance of bay grasses, it can help them learn about some Bay-related STEM careers.